Ticket #888: snmp__tcpCurrEstab

#!/usr/bin/perl -w
# -*- perl -*-
#
# Copyright (C) 2004 Jimmy Olsen, Dagfinn Ilmari Mannsaaker
# Copyright (C) 2010 Aleksandar Lazic
#
# This plugin is copied from snmp__processes
#
# This program is free software; you can redistribute it and/or
# modify it under the terms of the GNU General Public License
# as published by the Free Software Foundation; version 2 dated June,
# 1991.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program; if not, write to the Free Software
# Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
#
#
#%# family=snmpauto
#%# capabilities=snmpconf

use strict;
use Net::SNMP;

my $DEBUG = 0;
my $MAXLABEL = 20;

my $host      = $ENV{host}      || undef;
my $port      = $ENV{port}      || 161;
my $community = $ENV{community} || "public";

my $response;

if (defined $ARGV[0] and $ARGV[0] eq "snmpconf")
{
        # .iso.org.dod.internet.mgmt.mib-2.tcp.tcpCurrEstab.0
        print "require .1.3.6.1.2.1.6.9.0 [0-9]\n"; # Number
        exit 0;
}

if ($0 =~ /^(?:|.*\/)snmp_([^_]+)_tcpCurrEstab$/)
{
        $host  = $1;
        if ($host =~ /^([^:]+):(\d+)$/)
        {
                $host = $1;
                $port = $2;
        }
}
elsif (!defined($host))
{
        print "# Debug: $0 -- $1\n" if $DEBUG;
        die "# Error: couldn't understand what I'm supposed to monitor.";
}

my ($session, $error) = Net::SNMP->session(
                -hostname  => $host,
                -community => $community,
                -port      => $port
        );

if (!defined ($session))
{
        die "Croaking: $error";
}

if (defined $ARGV[0] and $ARGV[0] eq "config")
{
        print "host_name $host\n" unless $host eq 'localhost';
        print "graph_title Number of current established tcp connections 
graph_args --base 1000 -l 0 
graph_vlabel number of tcp connections
graph_category network
graph_info This graph shows the number of current established tcp connections
tcpcon.label connections
tcpcon.draw LINE2
tcpcon.info The number of tcp connections.
";

        exit 0;
}

print "tcpcon.value ", &get_single ($session, ".1.3.6.1.2.1.6.9.0"), "\n";

sub get_single
{
        my $handle = shift;
        my $oid    = shift;

        print "# Getting single $oid...\n" if $DEBUG;

        $response = $handle->get_request ($oid);

        if (!defined $response->{$oid})
        {
            return undef;
        }
        else
        {
            return $response->{$oid};
        }
}